176 research outputs found

    Preparation and Characterization of Various Interstitial N-Doped TiO2 Catalysts from Different Nitrogen Dopants for the Treatment of Polluted Water

    Get PDF
    In this work N-doped TiO2 nano particle photocatalysts were prepared through a sol-gel procedure using three different types of nitrogen dopants urea, diethanolamine (DEA) and triethylamine (TEN). Multiple techniques (XRD, TEM, SEM, EDX, BET, Raman and UV-Visible absorption) were commanded to characterize the crystal structure of N-doped TiO2. The catalytic activity of the N-doped TiO2 under ultraviolet (UV) and visible light irradiation is evidenced by the decomposition of 2-chlorophenol, showing that nitrogen atoms in the N-doped TiO2 are responsible for the visible light catalytic activity. It is suggested that doped nitrogen here is located at the interstitial site of TiO2 lattice. Amongst investigated nitrogen precursors diethanolamine provided the highest visible light absorption ability of interstitial N-doped TiO2 with the smallest energy band gap and the smallest anatase crystal size, resulting in the highest efficiency in 2-cholorophenol degradation. The photocatalytic activity and 2-CP mineralization ability of all N-doped TiO2 can be arranged in the following order:  TiO2/DEA > TiO2/TEN > TiO2/UREA > un-doped TiO2. Keywords: 2-chlorophenol, Photocatalytic degradation, N-doped TiO2, Different Nitrogen Dopants, urea, diethanolamine (DEA), triethylamine (TEN) and Catalytic Activity

    Hydrogels and Their Combination with Liposomes, Niosomes, or Transfersomes for Dermal and Transdermal Drug Delivery

    Get PDF
    Polymeric networks that retain and absorb substantial amount of water or biological fluids and resemble as a biological tissue are defined as hydrogels. On the other hand, liposomes, transfersomes and niosomes are lipid carriers, which represent one of the major research and development focus areas of the pharmaceutical industry. They have great potential as lipid vehicles that are able to enhance permeation of drugs across the intact skin and can act as local depot for the drug to sustain and control its delivery. Lipid carrier and hydrogel combinations offer transdermal drug delivery of great potential to enhance systemic effects of both hydrophilic and lipophilic drugs. Also, lipid carriers can target drugs to skin appendages and improve transdermal delivery. Lipid carrier proform systems in the form of gelly liquid crystals can also be used transdermally for better drug absorption enhancement. This review highlights the potential of hydrogels and emulgels with or without lipid nanocarriers for dermal and transdermal application

    Development of two reference materials for all trans-retinol, retinyl palmitate, α- and γ-tocopherol in milk powder and infant formula

    Get PDF
    AbstractVitamins are important food constituents that can be present in almost every foodstuff. Food quality and safety depends on food surveillance by reliable quantitative analysis enabled by appropriate quality control. Certified matrix reference materials are versatile tools to support quality assurance and control. However, in the case of vitamins, which are important in various foods, there is a lack of matrix reference materials. Two certified reference materials for the determination of all–trans-retinol, retinyl palmitate, and α- and γ-tocopherol in milk powder and infant formula have been developed by the National Institute of Standards, Egypt. This article presents the preparation, characterization, homogeneity, and stability testing as well as statistical treatment of data and certified value assignment. The assignment of the certified values and associated uncertainties in the prepared natural-matrix reference materials were based on the widely used approach of combining data from independent and reliable analytical methods

    Design, synthesis and cytotoxic evaluation of 2-amino-4- aryl-6-substituted pyridine-3,5-dicarbonitrile derivatives

    Get PDF
    Purpose: To synthesize novel pyridine derivatives and evaluate their efficiency as potent inhibitors of cyclin dependent kinase 2 (CDK2) enzyme for cancer therapy.Methods: Pyridine scaffold were synthesized using one-pot multicomponent condensation reaction of arylidine with different primary amines. The cytotoxic potential of the new compounds was assessed using various cell lines. Furthermore, molecular docking studies based on the crystal structure of CDK2 was carried out to determine the possible binding modes that influence the anticancer activities.Results: The results indicate that one-pot multicomponent reaction generated a series of functionalized pyridines with good yield. In vitro cytotoxicity study revealed superior cytotoxicity of the designed compounds against prostate and cervical cancer cell lines compared to 5-fluorouracil (standard anticancer compound) with half-maximal inhibitory concentration (IC50) values of 0.1 – 0.85 and 1.2 –74.1 μM, respectively. Finally, molecular modeling simulation of the newly synthesized compounds showed that they fit well and are stabilized into CDK2 active site via hydrogen bonding and hydrophobic interactions.Conclusion: The results indicate that the newly synthesized pyridine can exert potent anticancer activity presumably via inhibition of CDK2. However, this will need to be confirmed in in vivo studies

    Cerebralna listerioza u deve na području Qassim u Središnjoj Saudijskoj Arabiji - prikaz slučajaDeva

    Get PDF
    A she-camel of about 6 years of age with neurological signs was admitted to the University Veterinary Teaching Hospital at Qassim, central Saudi Arabia, for diagnosis and treatment. Clinical examination showed lack of coordination of movements, Parkinson’s-like tremors of the head and lower lip paralysis. No parasite was detected in the stained blood smear, and except for leukocytosis and monocytosis, the result of the complete blood count (CBC) was normal. The results of the liver and kidney function tests were normal. The animal was infused with 4 units of 5% dextrose saline and injected with vitamin B1 and selenium preparations for the nervous manifestations. However, its health deteriorated rapidly and it was on lateral recumbency by the second day of admission. It died after one more day and was necropsied to investigate the cause of death. Postmortem examination showed slight congestion of the liver and the kidneys. The heart, meninges and the brain were congested and haemorrhagic. Histopathological examination showed acute lymphocytic meningeoencephalomyelitis in the medulla oblongata and spinal cord. Micro-abscesses containing neutrophils were seen in the medulla oblongata. Colonies of Listeria monocytogenes were obtained when the brain tissue was cultured in a cold environment. Smears made from the colonies showed Gram positive cocco-bacilli. Listeria monocytogenes was confirmed by PCR on DNA extracted from brain tissue.Deva u dobi od šest godina s neurološkim znakovima bila je radi dijagnoze i liječenja primljena na kliniku Veterinarskog Sveučilišta u Qassimu, Središnja Saudijska Arabija. Kliničkom pretragom ustanovljena je nekoordiniranost pokreta, tremor glave i paraliza donje usne slično kao kod Parkinsonove bolesti. U obojenim razmascima krvi nisu bili ustanovljeni paraziti, a hematološki nalaz bio je normalan osim što je ustanovljena leukocitoza i monocitoza. Nalazi funkcije jetara i bubrega bili su u fi ziološkim granicama. Životinja je dobila infuziju 4 jedinice 5% fiziološke otopine dekstroze s vitaminom B1 i preparatima selena zbog živčanih znakova. Ipak se njezino zdravstveno stanje naglo pogoršavalo te je drugoga dana bespomoćno ležala na boku. Uginula je trećega dana od primitka na kliniku te je razuđena da bi se otkrio uzrok uginuća. Postmortem pretraga pokazala je blagu kongestiju jetara i bubrega. Ustanovljeni su kongestija i krvarenja u srcu, moždanim ovojnicama i mozgu. Patohistološka pretraga pokazala je akutni limfocitni meningoencefalomijelitis u produženoj i kralježničnoj moždini. U produženoj moždini nalazili su se mikroapscesi koji su sadržavali neutrofile. Listeria monocytogenes bila je izdvojena iz moždanoga tkiva uzgojem u hladnim uvjetima. U razmascima kolonija dokazani su grampozitivni kokobacili. Nalaz bakterije Listeria monocytogenes bio je povrđen lančanom reakcijom polimerazom u DNA ekstrahiranoj iz moždanoga tkiva
    corecore